<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    .bg{
        width:100px;
        height:100px;
        background-color: red;
        /* 盒子阴影
        1、水平有移动3、高斯模糊
        box-shadow: offsetx  offsery blur size color */
        box-shadow: 10px 10px 10px 10px#333;
    }
    </style>
</head>
<body>
    <div class="bg">
        
    </div>
</body>
</html>